In general, a typical lathe machine, such as an automated machine used in a commercial manufacturing environment, includes a chuck for clamping a part or workpiece to be machined, and a spindle arrangement connected to the chuck and a drive/drive control mechanism to cause desired rotation or movement of the part during the machining process. Parts are successively fed in and out of the lathe by a loading mechanism, and positioning of each these parts relative to the chuck when loaded is critical to the overall efficiency of the machining process and quality of the machined parts. Thus, a sensing arrangement is typically employed for sensing the presence or position of a part to allow a control processor to automatically detect when a part is ready for machining.
To date, because of the difficulty in delivering electrical power to a location on the chuck, known chucking arrangements have used either an air sensing arrangement coupled to the chuck, or sensor arrangements not located on the chuck. Air sensing arrangements have been formed by using a rotary union to inject compressed air into the chuck. However air circuits are limited in the input obtained from the circuit and are subject to contamination and are therefore a service issue. Additionally the compressed air is relatively expensive for a plant to supply. With respect to electronic sensing arrangements, a high speed and sealed commutator is not readily available for chuck applications. Sensing arrangements which are not located on the chuck suffer from reliability concerns as well as increased cost and complexity.
Therefore, a need exists for an electronic sensing arrangement which can be positioned on a chuck.